Phoenix estimates the stale shares ratio, so it's not accurate. As you know, what's accurate is the pool. 1 1/2 day mining at anorak tech, no stale at all.
I don't believe for a second that pool is reporting stale shares.
If the miner see's a stale share and it isn't reported at the pool, then the pool isn't reporting them
and they're lying to you.
The pool will always report more stale shares than the miner.
So yes, the miner can't see all the stale shares, but it it see's one then there was one.